Many methods have been suggested to transmit simple geographical information and traffic information to a  receiving part by using an analog or digital broadcasting system. Meanwhile, vehicle and private navigation require an electronic map of a region where a user is located along with Global Positioning System (GPS) signals.
Generally, an electronic map is provided in the form of a compressed database. So, it is stored in a memory of a navigation system and used when a navigation application program requires it. This type of electronic map has a problem that the size of the electronic map is different according to the amount of information reserved in it. Also, when geographic, road and topographic information are changed or updated, they should be stored in the same way as they are initially stored.
Therefore, conventional systems have problems that they should equip a high-capacity memory to store an electronic map in the memory and get a navigation service and that they need another network or a medium to upgrade data.